Air duct noise reduction structure and sound box

Abstract

The utility model discloses a kind of air deflector noise reduction structure and sound box, it is related to sound box technical field, wherein, air deflector noise reduction structure includes air deflector and noise reduction piece, the air deflector has port;The noise reduction piece includes stacked sound-absorbing cotton and at least one protective net, the noise reduction piece is sleeved in the air deflector and covers the port, the noise reduction piece is connected with the outer tube wall of the air deflector.

Description

Technical Field

[0001] This utility model relates to the field of speaker technology, and in particular to a noise reduction structure for an air duct and a speaker. Background Technology

[0002] As consumer and professional audio systems upgrade towards higher power and wider bandwidth, the airflow velocity inside the enclosure increases significantly. Turbulent noise and standing wave noise generated by the airflow within the ductwork become one of the main factors contributing to the degradation of overall sound quality. The traditional approach is to attach sound-absorbing materials such as glass wool and polyester fiber cotton to the walls of the ductwork to absorb aerodynamic noise.

[0003] However, since sound-absorbing cotton is directly exposed to airflow, its surface pores easily adsorb dust and other microparticles, causing increased flow resistance and decreased sound absorption performance. In addition, in humid environments, the moisture content of sound-absorbing cotton increases, which not only leads to deterioration of sound absorption performance but also makes it prone to mold growth, affecting its service life. Utility Model Content

[0004] The main objective of this invention is to propose a noise reduction structure for an air duct and a speaker enclosure, aiming to... To achieve the above objectives, the present invention proposes a noise reduction structure for air ducts, comprising: Air duct, the air duct having a port; A noise reduction component, comprising stacked sound-absorbing cotton and at least one protective net, wherein the noise reduction component is fitted onto the air duct and covers the port, and the noise reduction component is connected to the outer wall of the air duct.

[0005] This utility model also proposes a speaker, including the above-mentioned air duct noise reduction structure. Attached Figure Description

[0006] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0007] Figure 1 A schematic diagram of an embodiment of the noise reduction structure for the air duct provided by this utility model; Figure 2 for Figure 1 Enlarged view of section A in the middle; Figure 3 An exploded structural diagram of an embodiment of the noise reduction structure for the air duct of this utility model; Figure 4 A schematic diagram of a noise reduction component according to an embodiment of the present invention.

[0008] Explanation of icon numbers: 100. Noise reduction structure for air duct; 1. Air duct; 11. Port; 12. Connecting flange; 2. Noise reduction components; 21. Sound-absorbing cotton; 22. Protective net; 3. Fixing components.

[0009] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0010] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0011] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0012] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0013] This utility model proposes a noise reduction structure 100 for air ducts.

[0014] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4In one embodiment of the present invention, the air duct noise reduction structure 100 includes an air duct 1 and a noise reduction component 2. The air duct 1 has a port 11. The noise reduction component 2 includes stacked sound-absorbing cotton 21 and at least one protective net 22. The noise reduction component 2 is sleeved on the air duct 1 and covers the port 11. The noise reduction component 2 is connected to the outer wall of the air duct 1.

[0015] In this technical solution, the noise reduction component 2 is composed of sound-absorbing cotton 21 and at least one layer of protective mesh 22. The sound-absorbing cotton 21 is made of conventional polyester fiber cotton, and the protective mesh 22 is made of nylon monofilament woven mesh. The two can be pre-composite to form a soft and rollable noise reduction component 2 through hot pressing. This retains the porous sound absorption performance of the sound-absorbing cotton 21, while the mesh skeleton of the protective mesh 22 significantly increases the surface tear resistance. During installation, the noise reduction component 2 is completely wrapped around the outer periphery of the air duct 1, and its port 11 area is completely covered. The protective mesh 22 is located on the outside of the airflow, while the sound-absorbing cotton 21 is close to the duct wall. Since the protective mesh 22 first faces the ambient air, dust particles in the high-speed airflow are intercepted by the mesh and cannot directly penetrate into the interior of the sound-absorbing cotton 21, thereby keeping the pores of the sound-absorbing cotton 21 open for a long time, avoiding increased flow resistance and attenuation of sound absorption performance. At the same time, the protective mesh 22 itself does not absorb water. With its open pore structure, it can accelerate the evaporation of surface moisture, significantly reduce the moisture content of the sound-absorbing cotton 21, inhibit mold growth, and extend service life. When the speaker is operating, high-speed airflow enters and exits the cabinet through the air duct 1. The sound-absorbing cotton 21 effectively absorbs mid-to-high frequency noise generated by turbulence and standing waves through a porous dissipation mechanism. The protective mesh 22 acts as a barrier layer to prevent contaminants from entering and maintains the overall structural stability. Meanwhile, because the noise-reducing component 2 is located at the end of the air duct 1 and does not encroach on the internal flow channel, the airflow resistance remains essentially unchanged, thus maintaining the system's low-frequency response and phase inversion efficiency. When adjustment or replacement of the noise-reducing component 2 is required, only cutting the cable ties or re-ultrasonic welding is needed for non-destructive disassembly and assembly. The noise reduction component 2 can be fixed to the outer wall of the air duct 1 by ultrasonic welding. A raised rib is pre-set on the outer wall of the port 11 of the air duct 1. After the edge of the noise reduction component 2 overlaps, the protective net 22 and the raised rib are instantly fused together by an ultrasonic welding head to complete the circumferential continuous welding point. There are no additional consumables, the connection strength is high, and the welding area is located outside the airflow, so it does not affect the acoustic performance. Alternatively, a cable tie fixing method can be used. A flange is reserved at the overlap of the noise reduction component 2. The cable tie is inserted into the flange and locked in the annular groove on the outer wall of the air duct 1. This allows for quick disassembly and assembly, and is convenient for later maintenance and replacement. There are no restrictions on this method.

[0016] In one embodiment, the noise reduction component 2 includes a protective net 22, which is disposed on the side of the sound-absorbing cotton 21 facing the air duct 1. The protective net 22, located on the side of the sound-absorbing cotton 21 facing the air duct 1, is suitable for cases where the port 11 is an air outlet. The protective net 22 is directly attached to the outer surface of the port 11 of the air duct 1, while the sound-absorbing cotton 21 is located outside the protective net 22, forming a sequential structure of air duct 1 outer wall - protective net 22 - sound-absorbing cotton 21. In this case, the high-speed airflow inside the air duct 1 is discharged outward from the port 11, and the protective net 22 is the first to bear the airflow impact. The protective net 22 rectifies the discharged turbulent airflow, weakens airflow pulsation, reduces regenerated noise, and provides rigid support; it prevents the sound-absorbing cotton 21 from shifting, bubbling, or falling off due to airflow impact or vibration, ensuring long-term structural stability. The sound-absorbing cotton 21 is located outside the protective net 22, and can still fully absorb the medium and high frequency noise radiated from the air duct 1, maintaining a good noise reduction effect. Since the protective net 22 is supported in the inner layer, the surface of the sound-absorbing cotton 21 is not easy to collapse, the sound-absorbing surface remains intact, and the acoustic performance is stable.

[0017] In another embodiment, the noise reduction component 2 includes a protective net 22, which is disposed on the side of the sound-absorbing cotton 21 facing away from the air duct 1. The protective net 22, located on the side of the sound-absorbing cotton 21 facing away from the air duct 1, is suitable for situations where the port 11 is an air inlet. The protective net 22 is placed on the outside of the sound-absorbing cotton 21, and the sound-absorbing cotton 21 adheres to the outer surface of the port 11 of the air duct 1, forming a sequential structure of air duct 1 outer wall - sound-absorbing cotton 21 - protective net 22. In this case, external air enters the air duct 1 from the port 11, and the protective net 22 is the first to come into contact with the external environment. The protective net 22 acts as an outer barrier, intercepting pollutants such as dust and fiber particles in the external air, preventing them from directly intruding into the pores of the sound-absorbing cotton 21; the open mesh structure facilitates moisture evaporation, reducing the moisture content of the sound-absorbing cotton 21 and inhibiting mold and odor; it also provides external mechanical protection, preventing the sound-absorbing cotton 21 from being torn or worn by external forces. The sound-absorbing cotton 21 is located inside the protective net 22, and can still effectively absorb the airflow noise entering the air duct 1 and the standing wave noise reflected inside the box; protected by the protective net 22, the pores remain unobstructed, and the sound absorption performance is stable for a long time; constrained by the protective net 22 and the pipe wall on both sides, the vibration amplitude is reduced, and abnormal noise is avoided.

[0018] Please see Figure 3 and Figure 4In one embodiment, the noise reduction component 2 includes two protective nets 22, with the sound-absorbing cotton 21 disposed between the two protective nets 22. The two layers of protective nets 22 sandwich the sound-absorbing cotton 21, forming a protective net 22-sound-absorbing cotton 21-protective net 22 sandwich structure. This structure can be pre-formed into a soft, rollable blanket-like whole through hot pressing, and then wrapped around the outer periphery of the port 11 of the air duct 1, completely covering the port 11 area. The two layers of protective nets 22 can be made of the same or different materials of nylon monofilament woven mesh, both possessing high sound transmission, low flow resistance, and oil and moisture resistance. The outer protective net 22, as the first barrier, directly faces the ambient air, intercepting dust, oil fumes, fiber particles, and flying insects, preventing pollutants from penetrating the sound-absorbing cotton 21; its open-pore structure allows for rapid moisture removal, inhibiting mold growth and keeping the sound-absorbing cotton 21 dry. The inner protective mesh 22, acting as a second barrier, adheres to the outer wall of the air duct 1. On one hand, it straightens the high-speed airflow, weakens turbulent pulsations, and reduces regenerated noise; on the other hand, it provides rigid support for the sound-absorbing cotton 21, preventing it from being blown down or partially blocked by the airflow, thus keeping the flow channel unobstructed. The sound-absorbing cotton 21, located between the two protective meshes 22, is always in a bidirectional constraint state. It can fully receive and dissipate the mid-to-high frequency noise radiated from the air duct 1, while avoiding displacement, bubbling, or detachment due to vibration or airflow peeling force. At the same time, the high transmittance of the double-layer mesh ensures that the sound absorption performance of the sound-absorbing cotton 21 is almost unaffected.

[0019] In one embodiment, the sound-absorbing cotton 21 is heat-pressed to two protective nets 22 on both sides. First, two layers of protective nets 22 are laid on the inner and outer surfaces of the sound-absorbing cotton 21, and after alignment, they are fed into a hot-pressing roller assembly. Under the combined action of temperature and pressure, the monofilaments of the protective nets 22 partially melt and embed into the fiber gaps on the surface of the sound-absorbing cotton 21. After cooling, an integrated composite sheet of net-cotton-net is formed. This sheet is soft and rollable, and can be directly wrapped around the outer periphery of port 11 of the air duct 1, completely covering the port 11 area. After hot pressing, the surface fibers of the sound-absorbing cotton 21 and the protective nets 22 are micro-fused together, forming numerous tiny anchor points, significantly improving peel strength and maintaining positional stability under long-term vibration or airflow impact. No adhesive is required, avoiding the risk of formaldehyde volatilization and adhesive layer aging. Simultaneously, the overall thickness is reduced, resulting in better flexibility, allowing for close contact with the outer wall of irregularly shaped elbows or reducing pipes, achieving a high degree of fit. The integrated composite sheet can be prefabricated in the factory, and on-site installation can be completed simply by cutting, wrapping and fixing, which greatly shortens the assembly time compared to traditional manual pasting; due to the high sound transmission of the double-layer protective net 22, the sound absorption performance of the sound-absorbing cotton 21 is almost unaffected, and the mid-to-high frequency noise reduction effect is stable; and the overall structure formed by hot pressing can reduce the shedding rate of the sound-absorbing cotton 21 and extend its service life.

[0020] In one embodiment, the diameter of the noise-reducing component 2 is larger than the diameter of the port 11. The diameter of the noise-reducing component 2 (protective mesh 22 - sound-absorbing cotton 21 - protective mesh 22) is set to be significantly larger than the outer diameter of the port 11 of the air duct 1. During installation, after the noise-reducing component 2 covers the port 11, its edge naturally extends outward to form a ring-shaped skirt. This skirt completely covers the outside of the port 11 and can be fixed to the outer wall of the air duct 1 by ultrasonic welding or cable ties. The formation of the ring-shaped skirt allows the high-speed airflow to experience a gradual diffusion zone surrounded by sound-absorbing material when leaving or entering the port 11, effectively suppressing edge eddies and sudden noise expansion; at the same time, it covers any gaps or processing burrs that may exist on the wall of the air duct 1, preventing secondary howling caused by airflow excitation. The ring-shaped skirt serves as a redundant overlap area, providing sufficient fixing area. Ultrasonic welding points or cable ties can be evenly distributed along the circumference to avoid local stress concentration. During future maintenance, it can be recut, welded, or locked at any position along the ring-shaped skirt, achieving multiple disassembly and assembly without damaging the main sound-absorbing area. As the diameter increases, the effective sound absorption area increases accordingly, which can capture more mid-to-high frequency noise escaping from the edge of port 11, thus improving the overall noise reduction.

[0021] In one embodiment, the noise-reducing component 2 is welded to the outer peripheral wall of the air duct 1. The noise-reducing component 2 is wrapped around the outer periphery of the port 11 of the air duct 1, and its overlapping area is directly fused to the outer wall of the air duct 1 by ultrasonic welding. During welding, the local monofilaments of the outer protective mesh 22 melt simultaneously with the plastic of the same material as the surface of the air duct 1, and after cooling, a continuous and uniform annular weld is formed without the need for additional adhesives or mechanical fasteners. Welding makes the noise-reducing component 2 and the pipe wall a whole, which can withstand long-term vibration, impact and temperature cycling, and reduce the detachment rate of the noise-reducing component 2; the weld eliminates the overlapping gap, avoids airflow leakage from the edge slits and noise generation, and further reduces the noise of the port 11; there are no exposed parts such as screws and cable ties, the appearance is flat and the connection strength is high.

[0022] Please see Figure 1 and Figure 2In one embodiment, the noise reduction structure 100 of the air duct includes a fixing member 3, which is sleeved on the wall of the noise reduction member 2 and the air duct 1 to fix the noise reduction member 2. The fixing member 3 adopts a ring clamp structure (which can be an open ring, elastic retaining ring, etc.). During installation, the noise reduction member 2, which is composed of protective net 22, sound-absorbing cotton 21, and protective net 22, is first wrapped around the outer periphery of the port 11 of the air duct 1. Then, the fixing member 3 is slid in from the outside of the port 11 and sleeved on the outer surface of the noise reduction member 2. By tightening manually or with tools, the fixing member 3 generates a radial contraction force, pressing the noise reduction member 2 as a whole against the outer wall of the air duct 1 to form a uniform circumferential constraint. The fixing member 3 provides controllable and continuous radial pressure, so that the noise reduction member 2 and the pipe wall generate sufficient static friction to resist the relative slippage caused by high-speed airflow impact, mechanical vibration, and temperature changes. Its tightening amount is adjustable to adapt to different wall thicknesses or outer diameter tolerances, ensuring that it does not loosen over a long period of time. Meanwhile, a limiting groove can be set on the outer wall of the air duct 1 to allow the fixing component 3 to be inserted, limiting the displacement of the noise reduction component 2 and improving the installation stability and reliability of the noise reduction component 2. The clamping fixing does not require welding or adhesive, and on-site installation only requires two steps: fitting and tightening, shortening the disassembly and assembly time; the fixing component 3 can be repeatedly loosened and tightened, facilitating the overall replacement of the noise reduction component 2 during maintenance without leaving any residual glue or weld marks.

[0023] Please see Figure 1 and Figure 2In one embodiment, the air duct 1 is provided with a connecting flange 12 near the port 11. The connecting flange 12 has an opening communicating with the port 11. The noise reduction component 2 is sleeved on the end of the connecting flange 12 away from the air duct 1 and connected to the connecting flange 12. The air duct 1 is integrally formed or a ring-shaped connecting flange 12 is installed after the air duct 1 is near the outlet of the housing. The flange has a circular opening and is coaxially connected to the port 11 of the air duct 1. The noise reduction component 2 (a sandwich structure of protective net 22-sound absorbing cotton 21-protective net 22) is made into a short sleeve, the diameter of which is slightly larger than the outer diameter of the flange. During installation, the noise reduction component 2 is sleeved into the far end of the flange from the outside until the end face fits against the flange stop. Then, it is locked by ultrasonic welding, hot air welding or cable ties to continuously fix the edge of the noise reduction component 2 to the flange end face and outer periphery. The connecting flange 12 provides a flat and rigid installation platform for the noise reduction component 2, avoiding direct welding or grooving on the thin-walled air duct 1 and protecting the strength of the pipe opening. The flange opening connects to port 11 of the air duct 1. When the airflow passes through the opening, it is surrounded by the noise reduction component 2 around the flange, effectively suppressing edge eddies and sudden noise expansion. The noise reduction component 2 is fitted at the far end of the flange, and the sound-absorbing cotton 21 extends outward, with a sound-absorbing area larger than the cross-sectional area of ​​port 11, forming a progressive diffusion silencing section. The double-layer protective mesh 22 respectively undertakes the functions of rectification, dust prevention, and structural reinforcement. The edges are supported by the full circumference of the flange, significantly improving the peel resistance. A connecting flange 12 is provided to improve the installation position of the noise reduction component 2, greatly improving the installation strength and sealing performance. The flange end face provides a process benchmark for subsequent automated welding or quick snap-fit, making it suitable for mass production.

[0024] Please see Figure 2 and Figure 3In one embodiment, the cross-sectional area of ​​the opening gradually increases from the end near the air duct 1 to the end away from the air duct 1. The inner cavity of the connecting flange 12 is designed as a gently expanding channel, with the starting end connected to the port 11 of the air duct 1 at the same diameter, and the ending end expanding outward in a trumpet shape, forming an air passage with a continuously increasing cross-sectional area. The noise reduction component 2 is fitted onto the far end of the flange and covers the entire outer wall of the expansion section, and then forms a firm connection with the flange end face and outer perimeter by ultrasonic welding or snap-fit. The expansion opening utilizes the geometric characteristics of gradually increasing cross-section to gradually reduce the speed of the airflow ejected from the air duct 1 at high speed, converting dynamic pressure into static pressure, significantly weakening the turbulent pulsation and vortex shedding noise generated by the sudden expansion of port 11; at the same time, it avoids the standing wave reflection caused by the traditional right-angle step, improving the low-frequency response. The expansion opening and the outer noise reduction component 2 form an integrated airflow deceleration-sound energy absorption module, which reduces the turbulent noise and standing wave reflection of port 11 simultaneously without the need for an additional anechoic chamber; the length of the expansion section can be flexibly adjusted to adapt to different housing thicknesses and appearance requirements. When applied to the air outlet, this structure significantly reduces jet noise; when applied to the air inlet, it reduces intake turbulence noise and prevents external dust from directly entering the air duct 1. With the help of a flange transition and the expanded curved surface formed in one piece, the noise reduction component 2 only requires two steps for on-site installation: fitting and fixing, meeting the multiple needs of high-end audio systems for efficient noise reduction and quick installation and replacement.

[0025] This utility model also proposes a speaker, which includes a duct noise reduction structure 100. The specific structure of the duct noise reduction structure 100 is as described in the above embodiments. Since this speaker adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0026] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A noise reduction structure for an air duct, characterized in that, include: Air duct, the air duct having a port; A noise reduction component, comprising stacked sound-absorbing cotton and at least one protective net, wherein the noise reduction component is fitted onto the air duct and covers the port, and the noise reduction component is connected to the outer wall of the air duct.

2. The noise reduction structure of the air duct as described in claim 1, characterized in that, The noise reduction component includes a protective net, which is disposed on the side of the sound-absorbing cotton facing the air duct; or The noise reduction component includes a protective net, which is located on the side of the sound-absorbing cotton facing away from the air duct.

3. The noise reduction structure for the air duct as described in claim 1, characterized in that, The noise reduction component includes two protective nets, and the sound-absorbing cotton is disposed between the two protective nets.

4. The noise reduction structure of the air duct as described in claim 3, characterized in that, The sound-absorbing cotton is heat-pressed to the two protective nets on both sides.

5. The noise reduction structure for the air duct as described in any one of claims 1 to 4, characterized in that, The diameter of the noise reduction component is larger than the diameter of the port.

6. The noise reduction structure for the air duct as described in any one of claims 1 to 4, characterized in that, The noise reduction component is welded to the outer peripheral wall of the air duct.

7. The noise reduction structure for the air duct as described in any one of claims 1 to 4, characterized in that, The noise reduction structure of the air duct includes a fixing member, which is sleeved on the wall of the noise reduction component and the air duct to fix the noise reduction component.

8. The noise reduction structure for the air duct as described in any one of claims 1 to 4, characterized in that, The air duct is provided with a connecting flange near the port, and the connecting flange has an opening communicating with the port. The noise reduction component is sleeved on the end of the connecting flange away from the air duct and is connected to the connecting flange.

9. The noise reduction structure for the air duct as described in claim 8, characterized in that, The cross-sectional area of ​​the opening gradually increases from the end closest to the air duct to the end furthest from the air duct.

10. A speaker, characterized in that, Including the air duct noise reduction structure as described in any one of claims 1 to 9.

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